1. Field of the Invention
This invention relates in general to intelligent telecommunications networks. In particular, the invention relates to a packet-based service node and intelligent peripheral that allows for maintaining adherence to an existing circuit-switched intelligent network call control model.
2. Background Art
Intelligent Network (xe2x80x9cINxe2x80x9d) services have become an integral aspect of modern telecommunications. Toll free number service, caller ID, virtual private networks and number portability are just a few of the many Intelligent Network services that are demanded by telecommunications customers today and accordingly must be offered and implemented by telephone service providers.
Existing implementations of circuit-switched Intelligent Networks commonly adopt and conform to the Bellcore GR-1129 standard, which specifies a circuit-switched interface between two primary components of such an Intelligent Network: the Service Switching Point (xe2x80x9cSSPxe2x80x9d) and the Service Node/intelligent Peripheral (xe2x80x9cSN/IPxe2x80x9d). A Service Switching Point is a switch that routes calls and is capable of querying external service applications or databases to process calls with intelligent features. The Service Switching Point queries a Service Control Point (xe2x80x9cSCPxe2x80x9d) to invoke many Intelligent Network features.
The Service Control Point is an intelligent, highly reliable server that processes the service logic and subscriber databases for executing Intelligent Network services. Existing telecommunications systems typically include Service Control Points programmed to provide information, such as toll free telephone number references or call routing instructions, for use by other components of the Intelligent Network. A Service Control Point in a modern Intelligent Network typically resides on a Signaling System 7 (xe2x80x9cSS7xe2x80x9d) signaling network, through which it can communicate with a Service Switching Point.
With the information and logic provided to the Service Switching Point by the Service Control Point, the Service Switching Point can utilize the ISDN PRI/BRI interface specified by the GR-1129 standard to interact with a SN/IP. In the GR-1129 call control model, a SN/IP is commonly used as a resource server that provides information to a network user and/or collects information from a network user via a circuit-switched bearer connection. The SN/IP typically uses subscriber-specific data stored on a Service Control Point to provide the call services. Therefore, in the call control model of a GR1129 enabled circuit-switched Intelligent Network, the Service.
Existing implementations of circuit-switched Intelligent Networks commonly adopt and conform to the Bellcore GR-1129 standard (Bellcore Gr-1129-CORE, xe2x80x9cAINGR: Switch-Intelligent Peripheral Interface (IPI)xe2x80x9d, Issue 3, September 1977), which specifies a circuit-switched interface between two primary components of such an Intelligent Network: the Service Switching Point (xe2x80x9cSSPxe2x80x9d) and the Service Node/intelligent Peripheral (xe2x80x9cSN/IPxe2x80x9d). A Service Switching Point is a switch that routes calls and is capable of querying external service applications or databases to process calls with intelligent features. The Service Switching Point queries a Service Control Point (xe2x80x9cSCPxe2x80x9d) to invoke many Intelligent Network features. By routing voice communications over a common network, providers of multiple communications services can exploit and benefit from the efficiencies of packet communications, develop new services to take advantage of such convergence, and potentially avoid the added expense of developing and/or maintaining multiple networks.
One increasingly popular type of packet network utilizes the International Telecommunication Union H.323 standard, which provides a foundation for converged audio, video and data communications across packet-based networks that do not guarantee quality of service, such as TCP/IP. The H.323 standard is network, platform and application independent, and provides for applications and products that are interoperable among vendors. The actual protocols and message formats commonly implemented with H.323 networks are described by the H.225 standard, among others.
One proposed solution for implementing Intelligent Network functionality in a packet-based telecommunications network, such as a H.323 network, is the Bellcore SR-3511 standard. The Bellcore SR-3511 standard specifies a packet-based call control model featuring an application level Transaction Capabilities Application Part (xe2x80x9cTCAPxe2x80x9d) interface over a TCP/IP transport directly connecting a packet-based Service Control Point and a packet-based SN/IP. Functionally, the SR-3511 interface allows the Service Control Point to interact with the SN/IP by directly providing information to guide SN/IP actions, and gathering information from the SN/IP. The SR-3511 standard therefore provides for the same level of functionality that is currently implemented by the circuit-switched GR-1129 model of Service Control Point messaging through the Service Switching Point to an ISDN SN/IP interface.
However, while implementing the SR-3511 standard would offer communication service providers and consumers alike the many functional advantages of a packet-based network, service providers have already developed vast and complex Intelligent Network infrastructures based upon the existing circuit-switched telephony protocols and call model. Implementation of new call control models such as the SR-3511 standard would require extensive redesign and redevelopment of many aspects of hardware and software, thereby preventing the reuse of certain existing hardware and software in newly developed packet-based INs. Such substantial changes entail great effort and expense for network products developers and network service providers alike.
Accordingly, it would be highly beneficial, and therefore it is an object of this invention, to provide a packet-based Intelligent Network that fully exploits the benefits of packet networks and applications convergence, while minimizing the required changes from the existing circuit-switched call model to allow some degree of hardware and/or software reuse when transitioning from a circuit-switched to packet-based network.
It is also an object of this invention to implement an Intelligent Network based upon standard packet network communication protocols, such as H.323.
These and other objects of the present invention will become apparent to those of ordinary skill in the art in light of the present specifications, drawings and claims.
The invention allows a packet-based intelligent telecommunications network to retain the call control model of the circuit-switched Bellcore GR-1129 standard, while implementing standard packet network protocols. Messaging is exchanged between the Service Control Point and SN/IP through the Service Switching Point, as in the GR-1129 model. Messaging between the network Service Switching Point and the Service Control Point may occur according to standards and protocols common to circuit-switched networks, such as SS7 or TCP/IP. The interface between the Service Switching Point and SN/IP is packet-based, such as H.323, rather than that specified by the GR-1129 standard. However, commands provided for by the GR-1129 standard are embedded within the packet-based messaging between the Service Switching Point and SN/IP. For example, when the packet Intelligent Network is based upon an H.323 network, a message provided for by the GR-1129 model is embedded within the facility information element of a H.225 command.